mutter/clutter/clutter-paint-volume.c
Robert Bragg 7d8effd5e2 paint_volume: add private api to change reference actor
For Clone actors we will need a way to report the volume of the source
actor as the volume of the clone actor. To make this work though we need
to be able to replace the reference to the source actor with a reference
to the clone actor instead. This adds a private
_clutter_paint_volume_set_reference_actor function to do that.
2010-09-29 15:13:00 +01:00

926 lines
24 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib-object.h>
#include "clutter-private.h"
GType
clutter_paint_volume_get_type (void)
{
static GType our_type = 0;
if (G_UNLIKELY (our_type == 0))
our_type =
g_boxed_type_register_static (I_("ClutterPaintVolume"),
(GBoxedCopyFunc) clutter_paint_volume_copy,
(GBoxedFreeFunc) clutter_paint_volume_free);
return our_type;
}
/*<private>
* _clutter_paint_volume_new:
* @actor: a #ClutterActor
*
* Creates a new #ClutterPaintVolume for the given @actor.
*
* Return value: the newly allocated #ClutterPaintVolume. Use
* clutter_paint_volume_free() to free the resources it uses
*
* Since: 1.4
*/
ClutterPaintVolume *
_clutter_paint_volume_new (ClutterActor *actor)
{
ClutterPaintVolume *pv;
g_return_val_if_fail (actor != NULL, NULL);
pv = g_slice_new (ClutterPaintVolume);
pv->actor = g_object_ref (actor);
memset (pv->vertices, 0, 8 * sizeof (ClutterVertex));
pv->is_static = FALSE;
pv->is_empty = TRUE;
pv->is_axis_aligned = TRUE;
pv->is_complete = TRUE;
pv->is_2d = TRUE;
return pv;
}
/* Since paint volumes are used so heavily in a typical paint
* traversal of a Clutter scene graph and since paint volumes often
* have a very short life cycle that maps well to stack allocation we
* allow initializing a static ClutterPaintVolume variable to avoid
* hammering the slice allocator.
*
* We were seeing slice allocation take about 1% cumulative CPU time
* for some very simple clutter tests which although it isn't a *lot*
* this is an easy way to basically drop that to 0%.
*
* The PaintVolume will be internally marked as static and
* clutter_paint_volume_free should still be used to "free" static
* volumes. This allows us to potentially store dynamically allocated
* data inside paint volumes in the future since we would be able to
* free it during _paint_volume_free().
*/
void
_clutter_paint_volume_init_static (ClutterActor *actor,
ClutterPaintVolume *pv)
{
g_return_if_fail (actor != NULL);
pv->actor = g_object_ref (actor);
memset (pv->vertices, 0, 8 * sizeof (ClutterVertex));
pv->is_static = TRUE;
pv->is_empty = TRUE;
pv->is_axis_aligned = TRUE;
pv->is_complete = TRUE;
pv->is_2d = TRUE;
}
void
_clutter_paint_volume_copy_static (const ClutterPaintVolume *src_pv,
ClutterPaintVolume *dst_pv)
{
g_return_if_fail (src_pv != NULL && dst_pv != NULL);
memcpy (dst_pv, src_pv, sizeof (ClutterPaintVolume));
g_object_ref (dst_pv->actor);
dst_pv->is_static = TRUE;
}
/**
* clutter_paint_volume_copy:
* @pv: a #ClutterPaintVolume
*
* Copies @pv into a new #ClutterPaintVolume
*
* Return value: a newly allocated copy of a #ClutterPaintVolume
*
* Since: 1.4
*/
ClutterPaintVolume *
clutter_paint_volume_copy (const ClutterPaintVolume *pv)
{
ClutterPaintVolume *copy;
g_return_val_if_fail (pv != NULL, NULL);
copy = g_slice_dup (ClutterPaintVolume, pv);
if (copy->actor)
g_object_ref (copy->actor);
copy->is_static = FALSE;
return copy;
}
void
_clutter_paint_volume_set_from_volume (ClutterPaintVolume *pv,
const ClutterPaintVolume *src)
{
if (src->actor != pv->actor)
{
g_object_unref (pv->actor);
g_object_ref (src->actor);
}
memcpy (pv, src, sizeof (ClutterPaintVolume));
}
/**
* clutter_paint_volume_free:
* @pv: a #ClutterPaintVolume
*
* Frees the resources allocated by @pv
*
* Since: 1.4
*/
void
clutter_paint_volume_free (ClutterPaintVolume *pv)
{
g_return_if_fail (pv != NULL);
g_object_unref (pv->actor);
if (G_LIKELY (pv->is_static))
return;
g_slice_free (ClutterPaintVolume, pv);
}
/**
* clutter_paint_volume_set_origin:
* @pv: a #ClutterPaintVolume
* @origin: a #ClutterVertex
*
* Sets the origin of the paint volume.
*
* The origin is defined as the X, Y and Z coordinates of the top-left
* corner of an actor's paint volume, in actor coordinates.
*
* The default is origin is assumed at: (0, 0, 0)
*
* Since: 1.4
*/
void
clutter_paint_volume_set_origin (ClutterPaintVolume *pv,
const ClutterVertex *origin)
{
float dx = origin->x - pv->vertices[0].x;
float dy = origin->y - pv->vertices[0].y;
float dz = origin->z - pv->vertices[0].z;
int key_vertices[4] = {0, 1, 3, 4};
int i;
g_return_if_fail (pv != NULL);
g_return_if_fail (pv->is_axis_aligned);
/* If we change the origin then all the key vertices of the paint
* volume need to be shifted too... */
for (i = 0; i < 4; i++)
{
pv->vertices[key_vertices[i]].x += dx;
pv->vertices[key_vertices[i]].y += dy;
pv->vertices[key_vertices[i]].z += dz;
}
pv->is_complete = FALSE;
}
/**
* clutter_paint_volume_get_origin:
* @pv: a #ClutterPaintVolume
* @vertex: (out): the return location for a #ClutterVertex
*
* Retrieves the origin of the #ClutterPaintVolume.
*
* Since: 1.4
*/
void
clutter_paint_volume_get_origin (const ClutterPaintVolume *pv,
ClutterVertex *vertex)
{
g_return_if_fail (pv != NULL);
g_return_if_fail (vertex != NULL);
*vertex = pv->vertices[0];
}
static void
_clutter_paint_volume_update_is_empty (ClutterPaintVolume *pv)
{
if (pv->vertices[0].x == pv->vertices[1].x &&
pv->vertices[0].y == pv->vertices[3].y &&
pv->vertices[0].z == pv->vertices[4].z)
pv->is_empty = TRUE;
else
pv->is_empty = FALSE;
}
/**
* clutter_paint_volume_set_width:
* @pv: a #ClutterPaintVolume
* @width: the width of the paint volume, in pixels
*
* Sets the width of the paint volume.
*
* Since: 1.4
*/
void
clutter_paint_volume_set_width (ClutterPaintVolume *pv,
gfloat width)
{
gfloat right_xpos;
g_return_if_fail (pv != NULL);
g_return_if_fail (pv->is_axis_aligned);
g_return_if_fail (width >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
right_xpos = pv->vertices[0].x + width;
/* Move the right vertices of the paint box relative to the
* origin... */
pv->vertices[1].x = right_xpos;
/* pv->vertices[2].x = right_xpos; NB: updated lazily */
/* pv->vertices[5].x = right_xpos; NB: updated lazily */
/* pv->vertices[6].x = right_xpos; NB: updated lazily */
pv->is_complete = FALSE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_width:
* @pv: a #ClutterPaintVolume
*
* Retrieves the width set using clutter_paint_volume_get_width()
*
* Return value: the width, in pixels
*
* Since: 1.4
*/
gfloat
clutter_paint_volume_get_width (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
g_return_val_if_fail (pv->is_axis_aligned, 0);
if (pv->is_empty)
return 0;
else
return pv->vertices[1].x - pv->vertices[0].x;
}
/**
* clutter_paint_volume_set_height:
* @pv: a #ClutterPaintVolume
* @height: the height of the paint volume, in pixels
*
* Sets the height of the paint volume.
*
* Since: 1.4
*/
void
clutter_paint_volume_set_height (ClutterPaintVolume *pv,
gfloat height)
{
gfloat height_ypos;
g_return_if_fail (pv != NULL);
g_return_if_fail (pv->is_axis_aligned);
g_return_if_fail (height >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
height_ypos = pv->vertices[0].y + height;
/* Move the bottom vertices of the paint box relative to the
* origin... */
/* pv->vertices[2].y = height_ypos; NB: updated lazily */
pv->vertices[3].y = height_ypos;
/* pv->vertices[6].y = height_ypos; NB: updated lazily */
/* pv->vertices[7].y = height_ypos; NB: updated lazily */
pv->is_complete = FALSE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_height:
* @pv: a #ClutterPaintVolume
*
* Retrieves the height of the paint volume set using
* clutter_paint_volume_get_height()
*
* Return value: the height of the paint volume, in pixels
*
* Since: 1.4
*/
gfloat
clutter_paint_volume_get_height (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
g_return_val_if_fail (pv->is_axis_aligned, 0);
if (pv->is_empty)
return 0;
else
return pv->vertices[3].y - pv->vertices[0].y;
}
/**
* clutter_paint_volume_set_depth:
* @pv: a #ClutterPaintVolume
* @depth: the depth of the paint volume, in pixels
*
* Sets the depth of the paint volume.
*
* Since: 1.4
*/
void
clutter_paint_volume_set_depth (ClutterPaintVolume *pv,
gfloat depth)
{
gfloat depth_zpos;
g_return_if_fail (pv != NULL);
g_return_if_fail (pv->is_axis_aligned);
g_return_if_fail (depth >= 0.0f);
/* If the volume is currently empty then only the origin is
* currently valid */
if (pv->is_empty)
pv->vertices[1] = pv->vertices[3] = pv->vertices[4] = pv->vertices[0];
depth_zpos = pv->vertices[0].z + depth;
/* Move the back vertices of the paint box relative to the
* origin... */
pv->vertices[4].z = depth_zpos;
/* pv->vertices[5].z = depth_zpos; NB: updated lazily */
/* pv->vertices[6].z = depth_zpos; NB: updated lazily */
/* pv->vertices[7].z = depth_zpos; NB: updated lazily */
pv->is_complete = FALSE;
pv->is_2d = depth ? FALSE : TRUE;
_clutter_paint_volume_update_is_empty (pv);
}
/**
* clutter_paint_volume_get_depth:
* @pv: a #ClutterPaintVolume
*
* Retrieves the depth of the paint volume set using
* clutter_paint_volume_get_depth()
*
* Return value: the depth
*
* Since: 1.4
*/
gfloat
clutter_paint_volume_get_depth (const ClutterPaintVolume *pv)
{
g_return_val_if_fail (pv != NULL, 0.0);
g_return_val_if_fail (pv->is_axis_aligned, 0);
if (pv->is_empty)
return 0;
else
return pv->vertices[4].z - pv->vertices[0].z;
}
/**
* clutter_paint_volume_union:
* @pv: The first #ClutterPaintVolume and destination for resulting
* union
* @another_pv: A second #ClutterPaintVolume to union with @pv
*
* Updates the geometry of @pv to be the union bounding box that
* encompases @pv and @another_pv.
*
* Since: 1.4
*/
void
clutter_paint_volume_union (ClutterPaintVolume *pv,
const ClutterPaintVolume *another_pv)
{
int key_vertices[4] = {0, 1, 3, 4};
g_return_if_fail (pv != NULL);
g_return_if_fail (pv->is_axis_aligned);
g_return_if_fail (another_pv != NULL);
g_return_if_fail (another_pv->is_axis_aligned);
/* NB: we only have to update vertices 0, 1, 3 and 4
* (See the ClutterPaintVolume typedef for more details) */
/* We special case empty volumes because otherwise we'd end up
* calculating a bounding box that would enclose the origin of
* the empty volume which isn't desired.
*/
if (another_pv->is_empty)
return;
if (pv->is_empty)
{
int i;
for (i = 0; i < 4; i++)
pv->vertices[key_vertices[i]] = another_pv->vertices[key_vertices[i]];
pv->is_2d = another_pv->is_2d;
goto done;
}
/* grow left*/
/* left vertices 0, 3, 4, 7 */
if (another_pv->vertices[0].x < pv->vertices[0].x)
{
int min_x = another_pv->vertices[0].x;
pv->vertices[0].x = min_x;
pv->vertices[3].x = min_x;
pv->vertices[4].x = min_x;
/* pv->vertices[7].x = min_x; */
}
/* grow right */
/* right vertices 1, 2, 5, 6 */
if (another_pv->vertices[1].x > pv->vertices[1].x)
{
int max_x = another_pv->vertices[1].x;
pv->vertices[1].x = max_x;
/* pv->vertices[2].x = max_x; */
/* pv->vertices[5].x = max_x; */
/* pv->vertices[6].x = max_x; */
}
/* grow up */
/* top vertices 0, 1, 4, 5 */
if (another_pv->vertices[0].y < pv->vertices[0].y)
{
int min_y = another_pv->vertices[0].y;
pv->vertices[0].y = min_y;
pv->vertices[1].y = min_y;
pv->vertices[4].y = min_y;
/* pv->vertices[5].y = min_y; */
}
/* grow down */
/* bottom vertices 2, 3, 6, 7 */
if (another_pv->vertices[3].y > pv->vertices[3].y)
{
int may_y = another_pv->vertices[3].y;
/* pv->vertices[2].y = may_y; */
pv->vertices[3].y = may_y;
/* pv->vertices[6].y = may_y; */
/* pv->vertices[7].y = may_y; */
}
/* grow forward */
/* front vertices 0, 1, 2, 3 */
if (another_pv->vertices[0].z < pv->vertices[0].z)
{
int min_z = another_pv->vertices[0].z;
pv->vertices[0].z = min_z;
pv->vertices[1].z = min_z;
/* pv->vertices[2].z = min_z; */
pv->vertices[3].z = min_z;
}
/* grow backward */
/* back vertices 4, 5, 6, 7 */
if (another_pv->vertices[4].z > pv->vertices[4].z)
{
int maz_z = another_pv->vertices[4].z;
pv->vertices[4].z = maz_z;
/* pv->vertices[5].z = maz_z; */
/* pv->vertices[6].z = maz_z; */
/* pv->vertices[7].z = maz_z; */
}
if (pv->vertices[4].z == pv->vertices[0].z)
pv->is_2d = TRUE;
else
pv->is_2d = FALSE;
done:
pv->is_empty = FALSE;
pv->is_complete = FALSE;
}
/* The paint_volume setters only update vertices 0, 1, 3 and
* 4 since the others can be drived from them.
*
* This will set pv->completed = TRUE;
*/
void
_clutter_paint_volume_complete (ClutterPaintVolume *pv)
{
if (pv->is_complete || pv->is_empty)
return;
/* TODO: it is possible to complete non axis aligned volumes too. */
g_return_if_fail (pv->is_axis_aligned);
/* front-bottom-right */
pv->vertices[2].x = pv->vertices[1].x;
pv->vertices[2].y = pv->vertices[3].y;
pv->vertices[2].z = pv->vertices[0].z;
if (G_UNLIKELY (!pv->is_2d))
{
/* back-top-right */
pv->vertices[5].x = pv->vertices[1].x;
pv->vertices[5].y = pv->vertices[0].y;
pv->vertices[5].z = pv->vertices[4].z;
/* back-bottom-right */
pv->vertices[6].x = pv->vertices[1].x;
pv->vertices[6].y = pv->vertices[3].y;
pv->vertices[6].z = pv->vertices[4].z;
/* back-bottom-left */
pv->vertices[7].x = pv->vertices[0].x;
pv->vertices[7].y = pv->vertices[3].y;
pv->vertices[7].z = pv->vertices[4].z;
}
pv->is_complete = TRUE;
}
/*<private>
* _clutter_paint_volume_get_box:
* @pv: a #ClutterPaintVolume
* @box: a pixel aligned #ClutterGeometry
*
* Transforms a 3D paint volume into a 2D bounding box in the
* same coordinate space as the 3D paint volume.
*
* To get an actors "paint box" you should first project
* the paint volume into window coordinates before getting
* the 2D bounding box.
*
* <note>The coordinates of the returned box are not clamped to
* integer pixel values, if you need them to be clamped you can use
* clutter_actor_box_clamp_to_pixel()</note>
*
* Since: 1.4
*/
void
_clutter_paint_volume_get_bounding_box (ClutterPaintVolume *pv,
ClutterActorBox *box)
{
gfloat x_min, y_min, x_max, y_max;
ClutterVertex *vertices;
int count;
gint i;
g_return_if_fail (pv != NULL);
g_return_if_fail (box != NULL);
if (pv->is_empty)
{
box->x1 = box->x2 = pv->vertices[0].x;
box->y1 = box->y2 = pv->vertices[0].y;
return;
}
/* Updates the vertices we calculate lazily
* (See ClutterPaintVolume typedef for more details) */
_clutter_paint_volume_complete (pv);
vertices = pv->vertices;
x_min = x_max = vertices[0].x;
y_min = y_max = vertices[0].y;
/* Most actors are 2D so we only have to look at the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
count = 4;
else
count = 8;
for (i = 1; i < count; i++)
{
if (vertices[i].x < x_min)
x_min = vertices[i].x;
else if (vertices[i].x > x_max)
x_max = vertices[i].x;
if (vertices[i].y < y_min)
y_min = vertices[i].y;
else if (vertices[i].y > y_max)
y_max = vertices[i].y;
}
box->x1 = x_min;
box->y1 = y_min;
box->x2 = x_max;
box->y2 = y_max;
}
void
_clutter_paint_volume_project (ClutterPaintVolume *pv,
const CoglMatrix *modelview,
const CoglMatrix *projection,
const int *viewport)
{
int transform_count;
if (pv->is_empty)
{
/* Just transform the origin... */
_clutter_util_fully_transform_vertices (modelview,
projection,
viewport,
pv->vertices,
pv->vertices,
1);
return;
}
/* All the vertices must be up to date, since after the projection
* it wont be trivial to derive the other vertices. */
_clutter_paint_volume_complete (pv);
/* Most actors are 2D so we only have to transform the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
transform_count = 4;
else
transform_count = 8;
_clutter_util_fully_transform_vertices (modelview,
projection,
viewport,
pv->vertices,
pv->vertices,
transform_count);
pv->is_axis_aligned = FALSE;
}
void
_clutter_paint_volume_transform (ClutterPaintVolume *pv,
const CoglMatrix *matrix)
{
int transform_count;
int i;
if (pv->is_empty)
{
gfloat w = 1;
/* Just transform the origin */
cogl_matrix_transform_point (matrix,
&pv->vertices[0].x,
&pv->vertices[0].y,
&pv->vertices[0].z,
&w);
return;
}
/* All the vertices must be up to date, since after the transform
* it wont be trivial to derive the other vertices. */
_clutter_paint_volume_complete (pv);
/* Most actors are 2D so we only have to transform the front 4
* vertices of the paint volume... */
if (G_LIKELY (pv->is_2d))
transform_count = 4;
else
transform_count = 8;
for (i = 0; i < transform_count; i++)
{
gfloat w = 1;
cogl_matrix_transform_point (matrix,
&pv->vertices[i].x,
&pv->vertices[i].y,
&pv->vertices[i].z,
&w);
}
pv->is_axis_aligned = FALSE;
}
/* Given a paint volume that has been transformed by an arbitrary
* modelview and is no longer axis aligned, this derives a replacement
* that is axis aligned. */
void
_clutter_paint_volume_axis_align (ClutterPaintVolume *pv)
{
int count;
int i;
ClutterVertex origin;
float max_x;
float max_y;
float max_z;
if (pv->is_empty)
return;
g_return_if_fail (pv->is_complete);
if (G_LIKELY (pv->is_axis_aligned))
return;
if (G_LIKELY (pv->vertices[0].x == pv->vertices[1].x &&
pv->vertices[0].y == pv->vertices[3].y &&
pv->vertices[0].z == pv->vertices[4].y))
{
pv->is_axis_aligned = TRUE;
return;
}
origin = pv->vertices[0];
max_x = pv->vertices[0].x;
max_y = pv->vertices[0].y;
max_z = pv->vertices[0].z;
count = pv->is_2d ? 4 : 8;
for (i = 1; i < count; i++)
{
if (pv->vertices[i].x < origin.x)
origin.x = pv->vertices[i].x;
else if (pv->vertices[i].x > max_x)
max_x = pv->vertices[i].x;
if (pv->vertices[i].y < origin.y)
origin.y = pv->vertices[i].y;
else if (pv->vertices[i].y > max_y)
max_y = pv->vertices[i].y;
if (pv->vertices[i].z < origin.z)
origin.z = pv->vertices[i].z;
else if (pv->vertices[i].z > max_z)
max_z = pv->vertices[i].z;
}
pv->vertices[0] = origin;
pv->vertices[1].x = max_x;
pv->vertices[1].y = origin.y;
pv->vertices[1].z = origin.z;
pv->vertices[3].x = origin.x;
pv->vertices[3].y = max_y;
pv->vertices[3].z = origin.z;
pv->vertices[4].x = origin.x;
pv->vertices[4].y = origin.y;
pv->vertices[4].z = max_z;
pv->is_complete = FALSE;
pv->is_axis_aligned = TRUE;
if (pv->vertices[4].z == pv->vertices[0].z)
pv->is_2d = TRUE;
else
pv->is_2d = FALSE;
}
/*<private>
* _clutter_actor_set_default_paint_volume:
* @self: a #ClutterActor
* @check_gtype: if not %G_TYPE_INVALID, match the type of @self against
* this type
* @volume: the #ClutterPaintVolume to set
*
* Sets the default paint volume for @self.
*
* This function should be called by #ClutterActor sub-classes that follow
* the default assumption that their paint volume is defined by their
* allocation.
*
* If @check_gtype is not %G_TYPE_INVALID, this function will check the
* type of @self and only compute the paint volume if the type matches;
* this can be used to avoid computing the paint volume for sub-classes
* of an actor class
*
* Return value: %TRUE if the paint volume was set, and %FALSE otherwise
*/
gboolean
_clutter_actor_set_default_paint_volume (ClutterActor *self,
GType check_gtype,
ClutterPaintVolume *volume)
{
ClutterGeometry geometry = { 0, };
if (check_gtype != G_TYPE_INVALID)
{
if (G_OBJECT_TYPE (self) != check_gtype)
return FALSE;
}
/* calling clutter_actor_get_allocation_* can potentially be very
* expensive, as it can result in a synchronous full stage relayout
* and redraw
*/
if (!clutter_actor_has_allocation (self))
return FALSE;
clutter_actor_get_allocation_geometry (self, &geometry);
clutter_paint_volume_set_width (volume, geometry.width);
clutter_paint_volume_set_height (volume, geometry.height);
return TRUE;
}
/**
* clutter_paint_volume_set_from_allocation:
* @pv: a #ClutterPaintVolume
* @actor: a #ClutterActor
*
* Sets the #ClutterPaintVolume from the allocation of @actor.
*
* This function should be used when overriding the
* <function>get_paint_volume()</function> by #ClutterActor sub-classes that do
* not paint outside their allocation.
*
* A typical example is:
*
* |[
* static gboolean
* my_actor_get_paint_volume (ClutterActor *self,
* ClutterPaintVolume *volume)
* {
* return clutter_paint_volume_set_from_allocation (volume, self);
* }
* ]|
*
* Return value: %TRUE if the paint volume was successfully set, and %FALSE
* otherwise
*
* Since: 1.4
*/
gboolean
clutter_paint_volume_set_from_allocation (ClutterPaintVolume *pv,
ClutterActor *actor)
{
g_return_val_if_fail (pv != NULL, FALSE);
g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), FALSE);
return _clutter_actor_set_default_paint_volume (actor, G_TYPE_INVALID, pv);
}
/* Currently paint volumes are defined relative to a given actor, but
* in some cases it is desireable to be able to change the actor that
* a volume relates too (For instance for ClutterClone actors where we
* need to masquarade the source actors volume as the volume for the
* clone). */
void
_clutter_paint_volume_set_reference_actor (ClutterPaintVolume *pv,
ClutterActor *actor)
{
g_return_if_fail (pv != NULL);
g_object_unref (pv->actor);
pv->actor = g_object_ref (actor);
}